The last chapter in one of Australia’s biggest environmental battles is set to play out after mining giant Rio Tinto moved to finally shut down and rehabilitate the controversial Ranger uranium mine near the World Heritage-listed Kakadu National Park.

Rio, the world’s second-biggest miner by market value, told the Australian stock exchange on Wednesday it will compulsorily acquire the remaining shares it does not own in its subsidiary Energy Resources of Australia (ERA), taking full control of the contentious Ranger uranium mine and neighbouring Jabiluka deposit, one of the world’s richest known sources of untapped uranium.

ERA stopped mining uranium oxide at Ranger in 2012, but the cost of rehabilitating the mine is on track to exceed $2.2 billion and concerns have lingered among traditional owners, the Mirarr people, about ERA’s intentions, particularly after it was granted a 10-year mining lease extension over Jabiluka in March this year.

The push to mine Jabiluka sparked fierce opposition among traditional owners and environmental campaigners in 1998. Thousands of protesters took part in a human blockade at the site and hundreds were arrested in the ensuing clampdown.

The lease area covers a sacred site with hundreds of ancient rock art galleries. In the end, Jabiluka was never mined, and ERA pledged it would not develop the area as long as the Mirarr remain opposed to it.

Rio’s Australia chief executive Kellie Parker reaffirmed the dual London-Australia listed miner had “no intention to invest in mining or development of the Jabiluka deposit”.

“Proceeding with compulsory acquisition, after participating for our full entitlement in the ERA capital raising, underlines our commitment to Ranger’s rehabilitation,” Parker said.

ERA launched a $766.5 million capital raising in October to further fund rehabilitation of the Ranger mine. Rio bought its maximum entitlement in the raising, which pushed its shareholding up to 98 per cent from about 86 per cent.

It immediately said it would move to mop up the remaining shares held by minority investors in ERA under the compulsory acquisition rules of the Corporations Act for the same price, $0.002 per ERA share, as the entitlement offer.

“We remain committed to the successful rehabilitation of the Ranger Project Area to a standard that will establish an environment similar to the adjacent Kakadu National Park, a World Heritage site,” Parker said.

ERA’s board said it would keep shareholders informed of any subsequent developments and steps taken by Rio Tinto.

The global miner’s purchase of new shares under the capital raising will boost its voting power in ERA to 98.43 per cent, overwhelming a vocal minority of shareholders who were seeking to block Rio boosting its stake and who have been pushing for the Jabiluka deposit to be developed.

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